Estimate the concentration of carbon monoxide at the downwind edge of a city

The diagram shows the positions of the sun, moon and earth during spring tides, when the high tides are at their highest and low tides at their lowest. what is it about these positions that causes these high and low tides?

Which of the following words describe the reality that the universe looks the same from various perspective

37.0 °c = °f (human body normal temperature)